LOW-TEMPERATURE PHOTOLUMINESCENCE FROM BULK CDTE AND CD0.967ZN0.033TE

Low-temperature photoluminescence spectroscopy has been performed on bulk CdTe and Cd1-xZnxTe (x=0.033) in the emission region near the band-gap energy. A method to distinguish the free-exciton recombination band from other close-lying emissions in these materials is described. From the identification of the free-exciton emission, the band-gap energy was then determined. Radiative emission bands involving exciton-phonon quasiparticles were clearly observed above the band-gap energy at temperatures up to 40 K. The sample variation in the above-band-gap emission indicates that the exciton-phonon quasiparticle energy depends on the presence of donors and/or acceptors. In addition, the above-band-gap emission related to (e,h) transitions between the conduction band and valence band in these materials is observed. © 1995 American Institute of Physics.